Wireless communication device

Abstract

A wireless communication device is provided. The wireless communication device executes digital processing for a received UWB signal with use of an A/D converter having an adequate sample rate and resolution, and thus can obtain precise reception timing information. Since the sample rate of an A/D converted output is high, a timing detection circuit is formed of two-stage matched filters. The former-stage chip matched filter calculates the correlation between an input signal and a template signal. When a correct transmission pulse signal has arrived, the chip matched filter outputs to a frame matched filter an indication as to the presence of a pulse and reception timing. The latter-stage frame matched filter calculates the correlation value between a received frame signal and a spreading code to thereby determine whether the received frame is correct or incorrect, and adequately changes a threshold value of the chip matched filter.

1. A wireless communication device that receives an Ultra Wide Band signal employing a pulse in a wideband, comprising:
 an antenna part that receives an Ultra Wide Band signal; 
 a one-bit analog-to-digital converter that converts signal received by the antenna part into a digital signal; 
 N parallel counters that count the number of samples having a logical value of 1 in parallel for each of N samples, and output the counted number on a frame-by-frame basis, N denoting the number of samples in one frame time period; and 
 a timing detector that detects reception timing of a frame based on the number of samples having a logical value of 1 counted for each N samples. 
 
     
     
       2. The wireless communication device according to  claim 1 , wherein a conversion speed of the analog-to-digital converter is determined based on an employed communication method. 
     
     
       3. A wireless communication device that receives an Ultra Wide Band signal employing a pulse in a wideband, comprising:
 an antenna part that receives a Ultra Wide Band signal; 
 an oversampling analog-to-digital converter that converts a signal received by the antenna part into a digital signal by executing oversampling; 
 a timing detector that detects reception timing based on the digital signal output from the analog-to-digital converter, and 
 wherein the oversampling analog-to-digital converter includes a one-bit analog-to-digital converter that converts a signal into a digital signal, and N parallel counters that count the number of samples having a logical value of 1 in parallel for each of N samples and output the counted number on a frame-by-frame basis. 
 
     
     
       4. A wireless communication device that receives an Ultra Wide Band signal employing a pulse in a wideband, comprising:
 an antenna part that receives a Ultra Wide Band signal; 
 an oversampling analog-to-digital converter that converts a signal received by the antenna part into a digital signal by executing oversampling; and 
 a timing detector that detects reception timing based on the digital signal output from the analog-to-digital converter, and 
 wherein the timing detector includes two-stage matched filters including a chip matched filter and a frame matched filter wherein the chip matched filter calculates a correlation value between an input digital received signal and a certain template signal, and if the correlation value is larger than a threshold value, the chip matched filter recognizes that a correct transmission pulse signal has arrived, and outputs to the frame matched filter an indication as to presence of a pulse and a result of detection of reception timing. 
 
     
     
       5. The wireless communication device according to  claim 4 , wherein the frame matched filter calculates a correlation value between a received frame signal and a spreading code to thereby determine whether a received frame is correct or incorrect, and the frame matched filter finally outputs reception timing if a determination is made that the received frame is correct, and the frame matched filter instructs the chip matched filter to change the threshold value if a determination is made that the received frame is incorrect.